Method of treating pipe and boiler coverings



Patented Nov. 3, 1925 UNITED STATES ALVIN M. EI-IRET, or MT. AIRY, PENNSYLVANIA.

METHOD or ran Arms PIPE AND BQILER oovnnmos.

No Drawing.

ing material and has more especial relation to the treating of so-called 85% magnesia covering. Magnesia covering of the type under consideration is composed of carbonate of magnesium and not less than 10% of asbestos fibres. The resultant composition as formed into pipe and boiler coverings, according to microscopic tests, shows a surface having fine,'spherical particles, loosely held together, many of the particles even being separate from the covering surface. The entire covering is porous and of a more or less spongy consistency and has minute air cells. The asbestos fibres while dusted with magnesia particles are not coated. The result is that while 85% mag nesia pipe and boiler coverings are considered of the highest standard by engineers, nevertheless it is admitted that high de-, grees of temperature produce softening, crumbling and falling away of the covering particles thus decreasing insulating efficiency.

The leading object of the present invention is to overcome the above described disposition being possessed of greater strength and high temperature resisting characteristics.

A further object is to treat 85% magnesia pipe and boiler coverings with a solution of magnesium bi-carbonate for attaining the results sought by the leading object. Other and further objects not at this time appearing will be hereinafter described.

The invention consists of the method of treatment hereinafter described and finally claimed.

The nature, characteristic features and Application filed April 6, 192a serial No. 21,207.

scope of the'invention'willbe more fully iniderstood from the following description, According to the present invention I' take magnesium bi-carbonate solution, fwliichihas. high cryst'allizingtendencies and is a deriv- 85% magnesia pipe and boiler coverings by immerslng the same in said solution for ative of carbonate of magnesium, and treat a desired period of time and thereafter subject the treated covering to 'a desired degree of heat for a sufficient period of time in order to secure proper drying results. The period of immersion, degree of heat and time for drying may vary. Good results have been obtained, however, by merely dipping the covering in a solution of magnesium bicarbonate and permitting the covering to remain for several days in the presence of a temperature of about 70 F. Such treatment provides a covering of the character stated which is hard and dry and slightly.

heavier than standard 85% magnesia covering and the surface thereof shows a close binding of magnesia particles, free of loose spherical particles. The asbestos fibres of the covering furthermore are entirely coated and the minute air cells are effectively sealed. Thus not only is the covering greatly strengthened and high temperature resisting properties provided but because of the sealing of the air cells or pores a body of still or dead air may be precluded from passing through the covering thusv materially adding to the efficiency of the covering as aninsulator. Practice dictates that a covering treated as above will stand a tem' perature of 1000 F. Without softening or crumbling and falling away, thus greatly adding to the efiiciency of an already well recognized standard insulation the advantage of which is readily apparent.

While I have described particularly treat-, ing pipe and boiler coverings of magnesia and asbestos fibres it is apparent that I may treat other insulating materials with equally good results.

It will now be apparent that I have devised a novel and useful method of treating pipe and boiler coverings and like insulating material'which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description and while I have in thepresent instance shown and described the preferred embodiment thereof which has been found in practice to give satisfactory and reliable results, it is to be understood that the same is susceptible of modification in various particulars Without departing from the spirit or scope of the invention or sacrificing any of its advantages.

What I claim is: r

1. The method of treating pipe and boiler v covering composed of carbonate of magnesia and asbestos fibres which consists in treating the same With a solution of bicarbonate o1 magnesia.

2. The method of treating pipe and boiler covering composed of carbonate of magnesia and asbestos fibres Which consists in treating like insulating material to harden and increase the heat resisting characteristics thereof which consists in treating the same with a solution of bicarbonate of magnesia and thereafter drying said insulating material.

In testimony whereof, I have hereunto signed my name.

ALVIN M. EHRET. 

